Primer backing out due to aeroplane altitude pressure changes?

[sestoppelman]

So the next question is what sort of compressed load pushes the primer out ? I have some 4-5 % percent compressed loads-no primers being pushed out.

Basically not possible. I used to load my .280 to nearly the top with slow burning H4831 then seat a 160 bullet on top. Lots of compression!.
Primers dont back out for compression of powder.

 

[2L8]

110% Charge
Crimped
30' ASL to 12500' ASL (Unpressurized)
Primers were fine.

 

[Bullthrower338]

As with just about everything on the book of faces, bullshit.